Basically there are static nodes that are held remotely by users that have bought a set amount of coins. Those nodes work independently of one another to confirm that all coins are correct and syncs back to the main server. (That's my understanding from tinkering with the wallet, etc). Someone else may be able to add more to that. There are currently around 100 independent nodes in operation.

Owners of the company. Basically it's ensuring it's not a ponzi scheme where once they get enough money in; they will dump their shares/coins and leave everyone in the dust. If this happens.....I'd imagine a lot more people are going to be jumping into the Ripplesphere.